Product Memos

STATEMENT OF SYSTEM INTEGRITY FOR MVS (z/OS) FOR PHOENIX/PREFERENCE

January 18, 2006

Dear Customer: Below is a Statement of System Integrity for MVS for Pathlore's PHOENIX/PREFERENCE software.

As we understand it, System Integrity is defined for MVS as the inability of any program not authorized by a mechanism under the customer's control to:

1. Circumvent or disable store or fetch protection;

2. Access an OS password-protected or RACF-protected resource; or

3. Obtain control in an authorized state; that is, in supervisor state, with a protection key less than eight (8), or Authorized Program Facility (APF) authorized.

Provided below is when and why PHOENIX/PREFERENCE requires APF Authorization:

If only the VTAM teleprocessing Interface is used to access PHOENIX/PREFERENCE, then APF authorization is not required. However, if PHOENIX/PREFERENCE is APF authorized for a VTAM only interface, then VTAM will use its "authorized path" when processing PHOENIX/PREFERENCE VTAM requests.

If the PHOENIX/PREFERENCE Cross-Region Interface (CICS/TSO/IMS/IDMS) is used, then APF authorization is required. When the Cross-Region Interface is used, we (1) disable store/fetch protection to setup our SubSystem Control Table entry (SSCT) and our SubSystem Vector Table (SSVT) during initialization. Storage is obtained in CSA above the 16 Meg line to be used as communications buffers between PHOENIX/PREFERENCE and the Cross-Region Interface partner (CICS/TSO/IMS/IDMS) address space. Once this initialization is complete, the store/fetch protection is enabled. When PHOENIX/PREFERENCE is shutdown, we again disable store/fetch protection to closedown the interface. Once closedown of this interface is complete, the store/fetch protection is enabled.

During a user conversation with PHOENIX/PREFERENCE, our Cross-Region Interface program (running in CICS, TSO, IMS or IDMS region) switches to the PHOENIX/PREFERENCE PSW Key. This allows the interface program to pass and receive data to/from PHOENIX/PREFERENCE in the CSA storage. Once the data copy is complete, the interface program returns to its PSW Key. Thus, our interface program can only access storage allocated to PHOENIX/PREFERENCE. PHOENIX/PREFERENCE never attempts to defeat (2) OS password-protected or RACF-protected resource in an attempt to access secured data.

Our Cross-Region Interface program gains control (3) in supervisor state via an Open Exit Routine, SVC 99 Exit Routine and SVC 111 in order to connect to PHOENIX/PREFERENCE and to copy data into and out of our CSA storage during a user conversation. The interface does not disable store/fetch protection to accomplish this. It switches to the PHOENIX/PREFERENCE PSW Key to gain access to the communications storage allocated in CSA. Once the copy is complete, the interface program returns to its PSW Key.

With the availability of PHOENIX/PREFERENCE Release 7.9.1 Service Pack 1 all CSA/ECSA storage obtained by PHOENIX/PREFERENCE is in storage protection key 0. This will write protect our storage so that only authorized programs will be permitted to update it, eliminating potential MVS integrity issues.

Thanking you,

Sincerely,

SumTotal Systems